Improvements in or relating to drafting mechanisms for textile fibres



Sept. 13, 1955 J. NOGUERA 2,717,426

DRAFTING MECHANISMS FOR TEXTILE FIBRES Filed D80. 25, 1952 United States Patent Gffice 2,717,425 Patented Sept. 13,1955

DRAFTING MECHANISMS FOR TEXTILE FIBRES Joseph Noguera, Salford, Manchester, England, assignor to Casablancas High Draft Company Limited, Salford, Manchester, England, a British company Application December 23, 1952, Serial No. 327,663

Claims priority, application Great Britain January 30, 1952 13 Claims. (Cl. 19-135) This invention relates to drafting mechanisms for textile fibres, of the kind employing a number of drafting systems arranged side by side and each composed of consecutive pairs of rollers, the top rollers of adjoining drafting systems being carried and weighted from the centre by an arm which incorporates weighting means and is tion clear of the mechanism, two hands must be used, one

to press down the arm itself and the other to release the catch. In addition, in an eifort to streamline the arm as much as possible, it has been the practice to make the finger-grip provided on the catch mechanism unobtrusive and therefore relatively inaccessible and difiicult to manipulate.

A main object of the present invention is to overcome the aforementioned disadvantages by the provision of catch means for the arm which can be engaged or disengaged merely by pressing down with one hand on the forward end of the arm itself.

Inorder that the invention may be clearly understood and readily carried into effect two embodiments thereof will now be described in detail with reference to the accompanying drawings in which:

Figure 1 is a cross-sectional elevation through a drafting mechanism and shows a weighting and carrying arm partially broken away to expose an embodiment of the catch means according to the invention, the bottom rollers of the mechanism being indicated diagrammatically in chain dotted lines and parts of the mechanism having no bearing on the invention being omitted, and

Figure 2 is a cross-sectional elevation through a portion of the drafting mechanism similar to that shown in Figure 1, part of the mechanism being broken away to illustrate an alternative embodiment of the invention.

Referring now to the drawings, both embodiments of the invention are illustrated in their application to a roller weighting and carrying arm having spaced side plates 1 and a cover portion 1a which extends between the upper and end edges of the plates. The arm is mounted, in the usual manner, above the central necks 2 of the top rollers of roller pairs 3, 4 and 5 of adjoining drafting systems in a drafting mechanism, and is pivoted at the rear. between upstanding bracket plates 6 clamped on a bar 7 fixed at the rear of the mechanism.

The roller necks 2 are attached to the arm by means of a saddle assembly which is incorporated partially within the arm between the side plates 1. This saddle assembly includes a front weighting saddle 8 to which is secured the neck 2 of the top rollers of the front roller pairs 3 of adjoining drafting systems. The saddle 8 is extended rearwardly to provide an elongated lever 8a having a downwardly directed hook portion at the rear end for engaging a pivot pin 9 carried between the arm plates 1 a little behind the rear drafting rollers 5 and substantially parallel to the axes thereof. The rearward extension 8a of the front saddle lies within an open slot formed longitudinally in the upper part of a second saddle 10 which engages the top roller necks 2 betwe en the middle and rear roller pairs 4 and 5 respectively of the adjoining systems. The side edges of the aforesaid slot in the saddle 10 are formed with-upwardly extending projections 10a at or near the centre and a roller 11 is rotatably mounted between these projections so as to lie above and clear of the front saddle lever extension 8a. One end of a lever 12 is arranged to bear downwardly on the periphcry of the roller 11 as shown, the lever being pivotally located intermediate its length by means of a pivot'pin 13 secured between the arm side walls 1 and engaging in a recess 12a in the upper edge of the lever. The end of the lever 12 remote from the roller 11 is arranged to bear on coil springs 14 the opposite ends of which bear on the upper surface of the front saddle 8. With this arrangement, when the arm is retained in its normal working position, each spring 14 will press downwardly on the front saddle 8 to weight the top front rollers and also downwardly on the rear saddle 16, through the intermediary of the lever 12, to weight the middle and rear top rollers. I j

The saddle assembly described in the foregoing is only one example of several alternative arrangements which can be employed with weighting arms to which the invention may be applied, and the particular saddle assembly forms no part of the present invention. 7

The catch means illustrated in Figure 1', for holding down the arm in the weighting position, includes a catchmember 15 which is mounted to pivot on a pin 16 secured between the bracket plates 6. The catch member 15 is influenced by a spring 17 whereby a tail part 154 at the lower end of the catch member is normally held in abutting relationship with a fixed stop 18 which is also secured between the bracket plates 6. In this position, the upper part 15b of the catch member 15 extends upwardly and lies between the arm side plates 1 when the latter is in its lowered or operative position as illustrated. A stepped portion is formed at the upper end 1511 of the catch member, on the side thereof towards the front of the weighting arm, the influence of the spring 17 being such that it normally tends to rotate the catch member in an anti-clockwise direction as viewed in Figure 1 of the drawings, this movement being prevented by the fixed stop 18 as aforesaid.

For co-operation with the catch member 15, a dependent pawl 18c is mounted to pivot on a pin 19 secured between the arm plates 1. The lower end of this pawl is hooked at 18a for engagement with the catch member 15 beneath the pivotal axis of the latter. To this end the hooked end 18a of the pawl is provided with an upwardly directed flat engaging edge face which is arranged to abut a corresponding downwardly directed flat edge face of the catch member 15 as shown.

i The pawl 18c may conveniently be constructed in three layers 'of material and, at the upper end, part of the middle layer is cutaway for the reception of a lever 20 which is mounted to pivot on the same pin 19 as the pawl. One end of this lever 20a is arranged to abut the underside of an extension 18b on the pawl which extension lies on the side of the pawl pivot which is nearer the forward end of the arm and remote from the catch member 15. The other end 20b of the lever is arranged for coeoperation with the stepped portion 150 on the catch member 15 in a manner which will be later described. The pawl is influenced by a spring 21 which tends to move the pawl hooked portion 18a into engagement with the catch member 15, i. e. towards the rear end of the arm member. The lever 20 is influenced by a further spring .22 which is stronger than the pawl spring 21 and tends to rotate the lever in such a direction that the lever end 20a, by hearing on the pawl extension 13b, tends to press the pawl hooked portion 18a in a direction away from the catch member 15.

The purpose of the catch means as described is, as aforesaid, to hold the weighting arm down during operation of the drafting mechanism and thereby permit the weighting means, i, e. the springs 14, to apply the requisite pressure to the top rollers through the saddle assembly. The weighting pressure applied to the top rollers by the springs 14 is, of course, much more powerful than the pressure exerted by any of the springs 17 and 21 or 22 which are applied to the various members of the catch means.

In order to understand the operation of the catch means as described, it will be convenient first to consider the arm in a raised position to which it can be brought, when the catch means are released, by lifting the front end of the arm and turning the latter about its rear pivot. In this position of the arm, the catch member 15 will be held in position for engagement against its stop 18 under the influence of the spring 17, and the pawl 180 will be held in a disengaged or pre-engaging position under the influence of the lever spring 22. If now the arm is pivoted down from the raised position, a corner of the rearward end 2% of the lever 23 comes into contact with the step 150 on the catch member whereby the lever is rotated about pin 19 out of abutting relationship with the pawl extension 18b, the lever spring 22 being compressed by this rotation of lever 29. The pawl is then free to move under the influence of its spring 21 into engagement with the catch member 15. In order to lower the arm sufficiently for engagement to take place, it is only necessary slightly to press down the arm by hand beyond its normal weighting position and against the influence of the springs 14 whereby these springs 14 are additionally compressed by a small amount. When first engaged, the

co-operating surfaces of the hooked portion 18a of the pawl and on the catch member 15 are not in full abutting relationship but, as soon as manual pressure is removed from the arm, and the weighting pressure of the springs 14 permitted to re-assert itself, the upward force thereof causes the pawl 180 to exert an upward pull on the catch member 15 thereby bringing the aforesaid co-operating surfaces into full abutting relationship by rotating the catch member 15 slightly away from its step, against its spring influence, as shown in Figure 1. This rotation of the catch member 15 serves to move the stepped portion 150 of the catch member out of engagement with the member 20, which then returns into abutting relationship with the extension 18b on the pawl. The catch means is then effectively locked in the fully engaged position by the strong spring pressure 14 and, at the same time, is set for disengagement as soon as the spring pressure is relieved.

In order to release the arm, it is thus merely necessary to press down the top of the latter at the forward end so as to overcome the effect of the roller weighting pressure, thereby permitting the lever spring 22 to re-assert itself and snap the pawl 180 out of engagement with the catch member 15. The weighting arm is then free to be moved into the raised position about the rear pivot, whilst the various parts of the device are positioned under their various spring influences for automatic re-engagement as soon as the arm is again lowered.

In the alternative embodiment of the invention illustrated in Figure 2, the modified catch means is applied to a lever arm which is of the same type as that illustrated in Figure 1. This alternative catch means includes a catch member in the form of two similar circular plates 23. These plates are mounted to rotate on a common pivot pin 24 secured between the bracket plates 6 so as to lie just below the arm towards the rear end of the latter. The plates 23 are joined by a ring of axially extending pins 25 which are slightly inset from the plate circumferences and are influenced by a spring 26 which is mounted on a bar 27 between the bracket plates 6.

Positioned above the plate assembly is a dependent pawl 28 which is mounted near its upper end on a pivot pin 29. This pin 29 is secured between the arm side plates 1 and close to the under surface of the cover portion 1a. The lower depending end of the pawl 28 is hooked at 23a for engagement with one of the pins 25. The pawl 28 is centered by a spring 30 which is attached to the under surface of the arm cover portion 1a and has depending arms which bear on opposite side edges of the pawl. The result of this spring influence is that, when not engaging any other part of the device, the pawl is always urged into a dependent position in which it extends substantially perpendicularly with respect to the top cover portion of the arm. The spring 26 operates on the pins 25 in such manner as to ensure that, in the absence of any other influence, one of the pins of the assembly is always in a predetermined uppermost engaging position which lies slightly forward, towards the front end of the arm, in relation to a straight line joining the centres of the pawl and plate pivots.

If the arm is again considered to be in a raised position and, as previously, is pivoted down from this position and is pressed slightly beyond the normal roller weighting position against the influence of the weighting pressure, the hooked end 28a of the pawl will ride over and engage the uppermost pin 25, but it will be appreciated that the pin, pawl pivot and plate pivot are not at this moment in a straight line. When manual pressure is removed from the arm to permit the roller weighting pressure to re-assert itself, the arm will move slightly upwards under the influence of such pressure until the hooked end 28a of the pawl is firmly engaged with the pin 25. This movement serves to rotate the plate assembly or catch member against the influence of the spring 26, in a clockwise direction as viewed in Figure 2, so that the pawl pivot, plate pivot and engaged pin are then substantially in a straight line. In this position, the pawl and catch member are locked under the action of the roller weight: ing pressure and the plate spring 26 bears downwardly and outwardly on one of the pins as shown, this spring pressure tending to turn the plate assembly further round in the clockwise direction viewed as aforesaid. In other words the spring 26 tends to turn the plate assembly so that the next pin in succession after the engaged pin is brought into the pre-engaging uppermost position as previously defined.

To release the arm it is merely necessary again to press downwards on the forward end of the arm to overcome the upward thrust of the roller weighting pressure, Whereupon the plate spring 26 becomes operative to rotate the plates 23 as aforesaid and thereby move the engaged pin out of engagement with the pawl, whilst bringing the next pin into the defined uppermost position but behind the hooked pawl end. The arm can then be raised freely and the pawl under the influence of its own spring 30 returns to its normal or starting position. Once the arm is in the raised position, all the parts of the catch means will have returned to their pre-engaging positions so that-the arm can then be re-engaged merely by lowering it and pressing downwardly against the roller weighting pressure as previously described.

With such arrangements, the arm can readily be raised or lowered by an operator using only one hand, this being very convenient when other operations have to be performed simultaneously on the mechanism by the same operator.

I claim: 1. In a textile fibre drafting mechanism having top arm weighting, the provision of cooperating pawl and catch members for holding down the arm in the weighting position, spring means for automatically inter-engaging said members when the arm is depressed from an inoperative position, and further spring means, rendered operative by the reaction of the roller weighting pressure through the inter-engaged members, for automatically disengaging said members when the latter are relieved of said weighting pressure reaction. v

2. A drafting mechanism for textile fibres comprising consecutive pairs ofdrafting rollers, a top arm pivotally mounted on a fixture at the rear of the mechanism, means incorporated in said top arm for carrying the top rollers of said roller pairs, weighting springs acting between said arm and top rollers, cooperating pawl and catch members pivoted one on the arm and the other on said fixture for holding down said arm in its weighting position against the reaction of said weighting springs, spring means acting automatically to engage said pawl and catch members from disengaged positions when the arm is lowered from a raised position and depressed slightly beyond said working position against said weighting spring reaction, and further spring means, rendered operative by transmission of said weighting spring reaction through the pawl and catch members when the latter are engaged, for automatically returning said pawl and catch members to disengaged positions when the arm is depressed from the working position and then raised about its pivot.

3. A drafting mechanism for textile fibres comprising consecutive pairs of drafting rollers, a top arm pivotally mounted on a fixture at the rear of the mechanism, means incorporated in said top arm for carrying the top rollers of said roller pairs, weighting springs acting between said arm and top rollers, a spring influenced pawl depending from a pivot on said arm, a spring influenced trip lever ,1

arranged to hold the said pawl in a disengaged position against the action of said pawl spring, and a cooperating catch member pivoted on the fixture for limited rotation, away from a stop, against spring influence and adapted to trip said lever when the arm is depressed against the reaction of said weighting spring pressure, while the pawl and catch members are disengaged, to permit the pawl spring to move the pawl automatically into engagement with the said catch member, and re-assertion of said weighting spring pressure transmitted through the engaged pawl being arranged to rotate said catch member away from its stop and clear of said trip lever which latter then acts automatically to disengage the pawl when said weighting pressure is released by depression of the arm as aforesaid.

4. In a device of the kind described in which a movable weighting arm exerts weighting pressure on rollers of a drafting mechanism, inter-engageable members for holding the arm in its operative position when the members are engaged, automatically operating means operatively associated with said members causing said mem bers to interengage when the arm is moved from its inoperative position through its operative position, said members having cooperating parts held in locking engagement by the effect of the roller weighting pressure of the arm when the arm returns to its operative position, and automatically operating means operatively associated with said members effective for causing the disengagement of said members when the effect of the pressure of the arm on said parts of said members is removed by a subsequent moving of the arm through its operative position so that the arm is free to be moved to its inoperative position.

5. In a device of the kind described in which a movable weighting arm exerts weighting pressure on rollers of a drafting mechanism, inter-engageable members for holding the arm in its operative position when the members are engaged, one of said members being mounted on a fixed part of the drafting mechanism and the other of said members being mounted on the arm,

elastic operating means causing said membersto interengage when the arm is moved from its inoperative position through'its operative position, said members having cooperating parts held in frictional locking engagement by the effect of the roller weighting pressure of the arm when the arm returns to its operative position, and elastic means causing the disengagement of said members when the arm is subsequently moved through its operative position to'remove the effect'of the roller weighting pres-; sure of the arm onthe cooperating parts of said mern bers'so that the arm is free to'be moved to its inoperative po'sition,'*said elastic disengaging means being held 'inop-. erative by the frictional engagement of said parts of said members.

6. For use with a weighting arm member movably mounted to a frame member of a drafting mechanism, the combination of immobilizing catch means on one member biased to immobilizing position, latch means movably mounted on the other member and biased to latching engagement with the catch means and adapted in latching engagement to shift the immobilizing catch means to inoperative position, and overriding means applied to override the bias of the latch means whereby to shift the latch means out of latching position and release the immobilizing catch means to permit the immobilizing catch means to move into position to immobilize the overriding means whereby the latch means wll seek a latching engagement with the catch means.

7. The combination as claimed in claim 6 wherein said latch and catch means have mutually engaging surfaces for shifting the catch means to inoperative position on full engagement of the latch and catch means.

8. For use with a weighting arm member movably related to av frame member of a drafting mechanism in such wise that the arm member tends to move away from the frame member, the combination of latch means between the members biased to latching engagement and held to such engagement by the reactive force of the arm member, overriding means related to the latch means to normally override its bias and unlatch the same when the reactive force of the arm member is released, and immobilizing means for the overriding means biased to immobilizing position and related to the latch means for moving the immobilizing means to inoperative position when the latch means is in latched condition.

9. A drafting mechanism as claimed in claim 3 wherein the catch member is pivotally mounted intermediate its length and has an upper end which extends towards the arm for contacting the lever and a downwardly directed flat edge face below the pivot for engaging the pawl.

10. A drafting mechanism as claimed in claim 9 wherein the lower dependent end of the pawl is booked and provided with a flat upwardly directed edge face for engaging the said edge face of the catch member.

11. A drafting mechanism as claimed in claim 10 wherein the lever is mounted on the same pivot as the pawl and has a forward end which is urged by the lever spring influence, into engagement with an extension on the pawl and a rear end which is shaped to abut the upper end of the catch member, when the arm is depressed with the pawl and the catch member disengaged.

12. A mechanism is claimed in claim 11 wherein the pawl and catch member are arranged so that on initial engagement the respective flat edge faces are not in full abutting relationship but are moved into such relationship by relative rotation due to the re-assertion of said weighting pressure.

13. A mechanism as claimed in claim 2 wherein the catch member is in the form of two plates mounted for concentric rotation on the fixture and joined by a ring of axially extending pins and wherein the pawl depends from the lever and is hooked at the lower end for engagement with one of said pins, the pawl and catch member being influenced by springs which respectively tend to hold the former in a centered position and the latter with a pin in an upper pre-engaging position; which is v References Cited in the file of this patent slightly in front Of a line the and plate PiVOtS 5 I P in such manner that depression of the arm with the pawl and catch member disengaged causes the paw1 to ride 1,396,122 Johnson 3, 1921 over the aforesaid pin and into engagement therewith, 5 2,143,996 17, 1939 whilst re-assertion of the weighting pressure servesjto 5 Hess July 11, 4 pull the pin into line with the said pivots at the same time M08964 Nageh May 23, 19 rotating the catch member into a position in which the 2675587 Ralble et a1 P 1954 spring influence thereon urges the engaged pin out of FOREIGN PATENTS ng gem n with the pawl and the next pin into the en- 10 505,388 Belgium Sept 15, 1951 gagingposition when the arm is again depressed to relieve the weighting pressure. 

